The Science Inside Skin

the science inside

SKIN

AMERICANASSOCIATIONFORTHEADVANCEMENTOFSCIENCE Dear Reader: Science data and statistics are always changing, and it is important to be informed of current research. To help keep you up-to-date with the latest information on skin health, the American Association for the Advancement of Science would like to share the following updates regarding skin health:

N Major medical groups, including the CDC, recommend using sunscreen with an SPF of 15 or higher. However, a growing number of health care providers, including the M.D. Anderson Cancer Center, suggest products of SPF 30 or higher, particularly for those whose skin burns easily. (See references on pages 17, 32, and 45.)

N The number of doctor visits Americans make each year to get skin rashes checked out has dropped from 11.8 million to 10 million, according to the National Ambulatory Medical Care Survey: 2006 Summary, National Health Statistics Report No. 3. (See reference on page 23.) http://www.cdc.gov/nchs/data/nhsr/nhsr003.pdf is the most recent data. Check the site for regular updates to the statistics.

N According to the CDC’s National Program of Cancer Registries, 53,792 new cases of melanoma were reported in 2005, the most recent year for which statistics were available in Summer 2009. The National Cancer Institute estimates that 68,720 new cases will be diagnosed in 2009. (See reference on page 36.)

N Estimates vary as to the likelihood of developing melanoma during the average American’s lifetime. MedlinePlus, developed by the National Institutes of Health, estimates that 1 in 65 people will be diagnosed with melanoma at some point in their life. In 2009, The Skin Cancer Foundation predicted that 1 in 55 people will be diagnosed. (See reference on page 36.) As the science advances it is possible that more recent data will provide you with different numbers. While you can use this book as a starting point, check credible sites, such as those above, for results on the most up-to-date research. the science inside

SKIN

AMERICAN ASSOCIATION FOR THE ADVANCEMENT OFSCIENCE Published 2009 by The American Association for the Advancement of Science (AAAS) 1200 New York Avenue, NW Washington, DC 20005

978-0-87168-713-5

All rights reserved. Permission to reproduce this document for not-for-profit educa- tional purposes or for use in a review is hereby granted. No part of this book may be reproduced, stored in a retrieval system, or transmitted in any form, or by any means, electronic, mechanical, photocopy, recording, or otherwise, for commercial purposes without prior permission of AAAS.

This publication was made possible by a grant from Neutrogena.

Any interpretations and conclusions contained in this booklet are those of the authors and do not represent the views of the AAAS Board of Directors, the Council of AAAS, or its membership, or of Neutrogena. TABLEOFCONTENTS

INTRODUCTION: HEALTHY SKIN ...... 1

PART 1: SKIN FORM AND FUNCTION...... 3 What is skin? ...... 3 Why do we have skin? ...... 7

PART 2: HEALTHY SKIN...... 13 A lifetime of skin...... 13 Babies’ skin ...... 13 Teenagers’ skin ...... 15 Adults’ skin ...... 16 Healthy Hair and Nails ...... 19 Hair...... 19 Nails ...... 20

PART 3: SKIN DISORDERS AND TREATMENT...... 23 Skin Allergies...... 23 Eczema ...... 24 Contact dermatitis...... 24 Hives...... 25 Psoriasis ...... 27 Acne...... 28

PART 4: SUN EXPOSURE AND SKIN CANCER ...... 31 Sun and your skin ...... 31 What is skin cancer? ...... 32

PART 5: PROMISING RESEARCH: THE SKIN CARE OF TOMORROW. . . . 39 The basics of skin growth...... 39 The genetics of skin diseases ...... 39 Psoriasis ...... 40 Skin cancer...... 41 Acne...... 43 The important role of volunteers ...... 44 CONCLUSION: WHAT YOU CAN DO TO HAVE HEALTHIER SKIN ...... 45

APPENDIX 1: QUESTIONS TO ASK YOUR DOCTOR ABOUT YOUR SKIN ...... 47

APPENDIX 2: TAKING PART IN RESEARCH STUDIES— QUESTIONS TO ASK ...... 48

APPENDIX 3: OTHER SKIN CONDITIONS ...... 51

RESOURCES ...... 55

BIBLIOGRAPHY ...... 61

GLOSSARY ...... 65

ACKNOWLEDGEMENTS...... 69

PHOTO CREDITS ...... 70 INTRODUCTION: HEALTHY SKIN

kin is the body’s largest organ. It is also the most visible. A square inch of skinS has millions of cells and many nerve endings for sensing temperature, pain, pressure, and touch. It keeps us shel- tered from the elements and protects our insides from drying up.

Yet despite its toughness, skin is sensitive and can be damaged if it isn’t cared for. It requires our protection from the sun and from irritants. It needs our help in retaining moisture. It demands a little thought now and then.

In this book, you will learn all about your skin and how to take care of it. You will learn about skin ailments, from acne to skin cancer, and how to prevent them. The body sheds 30,000–40,000 dead Finally, we will look at the skin cells off its surface every minute. promising research scientists are doing to improve skin This amounts to nine pounds of care to keep your skin cells every year. healthy for a lifetime.

1 Skin: The Science Inside

Your skin is about 1/10 of an inch deep. The thinnest skin on your body is on your eyelids and on the inside of your elbows, and the thickest skin is on your palms, the soles of your feet, and your upper back. 2 Part 1: Skin Form and Function

HAIR EPIDERMIS PORE

NERVES DERMIS

FATTY OR SUBCUTANEOUS TISSUE HAIR FOLLICLE OIL GLAND BLOOD VESSELS SWEAT GLAND

A cross section What is skin? dermis mostly builds new skin of the Skin is actually made up of three cells and makes melanin, a three pigment that gives skin its layers different layers: of skin color. When we go outside, the • The epidermis melanin in our skin helps protect • The dermis us from being burned by the • The subcutaneous tissue sun’s ultraviolet rays.

The epidermis is the top layer Basal cells form the bottom of of skin, the part you see. Only as the epidermis. They divide and thick as a sheet of paper, the epi- form squamous cells, which 3 Skin: The Science Inside

produce keratin, a protein that of your immune system, are also reinforces your skin cells to help found in the basal layer of your protect you from the environment. epidermis.

As the basal cells divide, they push The dermis is the middle layer of the squamous cells up toward the our skin and makes up the majori- surface of your skin. As they move ty of it. It includes strong fibers up, the cells shrink, flatten, and called collagen and elastin, die. When they reach the top layer which give our skin strength and of the epidermis, they become the elasticity. stratum corneum, the outermost layer of skin that protects the The dermis contains sweat body. glands, oil glands, blood vessels, nerve fibers, lymphatic channels Melanocytes, which make the (the tubes that carry the bodily melanin in your skin, and fluid lymph), hair follicles, and Langerhans cells, which are part muscle cells.

A cross section of dermal and epidermal skin layers

4 Part 1: Skin Form and Function

Why are there different skin/hair colors? No one can deny the importance of skin main determining factor in what color a color within our society. Socially it can person’s skin will be, there is also another affect many things, but scientifically, skin pigment located in the dermis, which color is a lot less complex. contributes to the color. This yellow-colored pigment, called carotene, is covert- Most scientists agree that sunlight levels ed to vitamin A. Along with the pigments, determine whether a population tends to there are other factors that contribute to have light skin or dark skin. Sunlight con- skin color, such as the subcutaneous, or tains ultraviolet radiation (UV). The dark- fatty, tissue layer of skin. The way that er the skin, the less UV penetrates into it. light filters through this layer, as well as Too much UV is bad, because it destroys the other two layers of skin, has an effect an important nutrient, called folate. But on the way that skin color is perceived. some UV on our skin is good, because it Sometimes skin color develops unusually. helps our cells produce vitamin D, another Most people have moles (also known as important nutrient. birthmarks or nevi). Generally these are Where there is a lot of direct sunlight, just harmless clusters of darkly pigmented like in places close to the equator, people cells, but they should be watched because get more than enough sunlight to pro- changes can warn of developing skin can- duce vitamin D, but they are very suscep- cer. Vitiligo is an autoimmune disease tible to folate damage. Having dark skin that causes the skin to develop milky- that protects against the destruction of white patches. These develop because folate is advantageous in these parts of the body mistakenly makes antibodies the world. As a result, people with genes to its own melanin. for dark skin are healthier and produce Hair color is also a result of how much more offspring, who also have darker melanin a person has in their body. skin. After many generations, populations Individual hair shafts grow from follicles in these areas are mostly dark-skinned. that are rooted in the subcutaneous layer, Where sunlight is weak, making it diffi- passing through the dermis and epider- cult to produce enough vitamin D, the mis. Each hair is geneti- genes that produce light skin are favored, cally programmed allowing more UV to penetrate. In these to produce a certain parts of the world, people with those amount of melanin. genes are healthier and produce more The production of offspring. Over time, populations in these melanin occurs in the areas evolve to be light-skinned. middle layer of the hair shaft, referred to as the The skin colors themselves are the result cortex. When hair grays, of a pigment called melanin. Melanin is the cortex has slowed produced by melanocytes, cells that reside the amount of melanin in the skin’s top layer, or epidermis. There produced by the hair, are two types of melanin: eumelanin, causing the hair to turn which produces a brown to black color, gray and eventually and pheomelanin, which produces a red white. to yellow color. Although melanin is the

The color of skin is determined by the amount of a photoprotective pigment called melanin. Melanin comes in two forms: pheomelanin and eumelanin. Individuals with a light complexion produce more pheomelanin and those with a dark complexion produce more eumelanin. The number and size of melanin particles vary among individuals, producing a vast range of skin tones. 5 Skin: The Science Inside

Our sense of touch comes from the The subcutaneous tissue is the nerve endings found in the dermis. bottom layer of skin and is mostly made up of fat. It also contains our The top surface of the dermis and skin’s nerves and blood vessels, as the bottom surface of the epider- well as the roots of our oil and mis are covered with bumps that sweat glands and hair. help them fit together like puzzle pieces. The patterns these bumps A hair follicle is the tube-shaped create are unique to each of us sac that contains a hair. One hair and make up our fingerprints and grows out of each follicle and folli- other lines on our skin. cles are found throughout the body, except on the palms, soles, and lips.

These images show skin from different areas of the body. From left to right, they are from the palm or sole, the groin or armpit, and the rest of the body. The palm skin shows a much thicker epidermis (pale pink, top) than the others and is richly supplied with sensory nerves (yellow) in the dermis (dark pink). The skin from the groin shows a large hair arising from a follicle. A sebaceous gland (to the right of the hair) produces sebum, an oily substance which waterproofs the hair. A coiled sweat gland (blue) can also be seen leading to the skin’s surface through the hair’s shaft. The skin from other parts of the body has fewer sweat glands. 6 Part 1: Skin Form and Function

Oil glands are known as seba- Why do we have skin? ceous glands. They secrete an oily substance called sebum, We all know that skin keeps us which helps skin and hair retain from seeing each other’s insides. their moisture, protects them But, really, what is it supposed from friction, and acts as water- to do? Skin has four main jobs: proofing. Oil glands are found all over our bodies, but are concen- PROTECTION: Our skin is our trated on the scalp, face, chest, first line of defense against and genitals. infection. It keeps dirt, germs, and other harmful substances in Two types of sweat glands help the environment from getting to the body cool off. The eccrine our insides. glands produce sweat when we’re hot, stressed, or experiencing It also keeps us from drying out. strong emotions. They’re mostly The oil produced in our sebaceous found on our palms, soles, scalp, glands rises to the surface of our and underarms. The apocrine skin or hair and acts as a barrier glands develop during puberty so that only a certain amount of and produce sweat during times moisture can leave our bodies. of stress or strong emotion. Often our skin feels dry when too They’re mostly found under our much oil is removed from the skin arms and around nipples and gen- and moisture is allowed to escape itals. Sweat is released from the from the body. lower layers of the skin through pores, or tiny holes in the skin. TEMPERATURE REGULATION: Blood vessels in our skin expand In addition to containing all these and contract based on how warm things, the subcutaneous tissue or cold we are. When our body is also acts as a pillow to protect our hot, our blood vessels expand and internal organs from injury and bring warm blood closer to the holds in our body’s heat to keep surface of our skin, so that heat us warm. is released. Our sweat glands also make extra sweat so it can evapo- rate from the skin’s surface and cool us off. In this way, our skin acts like a built-in air condition- ing unit.

7 Skin: The Science Inside

When we’re cold, the opposite happens. The skin’s blood vessels nar- row, trying to keep the warm blood away from the surface of the skin. The skin will become pale and cold, and body heat will move inward toward our organs.

We also may develop goose bumps. When the body gets cold (or excit- ed), it causes the muscles attached to the base of each hair to pull it upright. This reflex, which all mammals and birds have, lets an animal warm up by trapping extra air closer to the skin so it can act as a warming layer. Animals also use this technique to make themselves look bigger to enemies. That’s why a cat looks bigger just before it gets into a fight with another animal, and why birds look fluffier when they’re sitting at a birdfeeder on a cold day. Goosebumps no longer serve a purpose for humans.

SENSATION: Nerves in our skin send signals through the spinal cord to our brain about the things around us. This tells us about our surroundings, like whether we’re touching wet mud or hard rock. Nerves also protect us by warning us about what can hurt us, like really hot or sharp things.

8 Part 1: Skin Form and Function

pain, and pressure (or touch) receptors. There are more pain nerve endings in our bodies than any other kind, which helps the body know where it is injured.

Other nerve endings in our skin lead to sexual excitement. These nerve endings stimulate the nervous and endocrine (hormonal) systems, which send mes- sages to the brain and the sexual organs to “turn them on.” (Of course, all senses play a role in sexuality, as does the mind, and not every touch is arousing.)

HEALTH WARNINGS: The skin can act as an early warning system to let us know that there’s Nerve receptors are not evenly something wrong elsewhere in spaced throughout the body. the body. The skin’s texture, Where they are closer together, temperature, and color all give we are more sensitive. They are hints about our general health furthest apart in the middle of and when something is wrong the back. They are closest on our elsewhere. For instance, if the hands, lips, face, neck, tongue, skin is hot, then we may have a and feet. In fact, each fingertip fever and be sick. A yellowish has about 100 touch receptors. color to the skin may point to problems with our liver. An There are about 20 different irregularly shaped brownish spot kinds of nerve endings; the most that suddenly appears even common ones are heat, cold, could point to skin cancer.

9 Skin: The Science Inside

Skin and the Body’s Systems The skin is one of the first defense mecha- nisms in your immune system. Your skin The integumentary system consists of has tiny glands that secrete sweat and oil. the skin, hair, nails, glands, and receptors. Those fluids help decrease the pH on the Its main function is to act as a barrier to surface of your skin to help kill microorgan- protect the body from the outside world. It isms. The enzymes in your sweat can digest also functions to retain body fluids, protect bacteria. against disease, eliminate waste products, and regulate body temperature. In order to The skin works with the excretory system do these things, the integumentary system by the removal of dead cells and sweat, works with all the other systems of your which contains waste products. Skin also body, each of which has a role to play in works to release waste, including water, maintaining the internal conditions that a salts, and urea, a toxic substance formed in human body needs to function properly. the body’s production of energy. Waste travels through the sweat gland and out of The integumentary system has many func- the body through sweat pores, which are tions, most of which are involved in pro- located in the epidermis. tecting and regulating your body’s internal functions in a variety of ways: By helping to synthesize and absorb vita- mins A, D, E, and K, the integumentary sys- • Protects the body’s internal living tissues tem works with the digestive system to and organs encourage the uptake of calcium from our diet. These substances enter the blood- • Protects against invasion by infectious stream though the capillary networks in organisms the skin. • Protects the body from drying out The integumentary system also works close- • Protects the body against abrupt changes ly with the circulatory system and the in temperature surface capillaries through your body. Because certain substances, such as hor- • Helps dispose of waste materials mones, can enter the bloodstream through the capillary networks in the skin, patches • Acts as a receptor for touch, pressure, can be used to deliver medications in this pain, heat, and cold manner for conditions ranging from heart problems (nitroglycerin) to smoking cessa- • Stores water and fat tion (nicotine patches). Capillaries near the surface of the skin open when your body • Helps in the production of vitamin D. needs to cool off and close when you need to conserve heat. Your body is a complicated system that consists of many subsystems that help to Your skin plays a vital role in your body keep it functioning properly. These subsys- regarding the sense of touch. The nervous tems serve a variety of purposes and system depends on neurons embedded in require certain materials to work right, as your skin to sense the outside world. It well as means of communicating informa- processes input from your senses, including tion to other parts of the body. Thus, the touch, and initiates actions based on those skin and other parts of the integumentary inputs. For example, when you stub your system work with other systems in your toe, nerve cells in the foot send signals up body to maintain and support the condi- the leg, through the spinal cord, and up tions that your cells, tissues, and organs into the brain. The nerve cell connections need to function properly. in the brain sense these signals as pain. As well as interacting with the body 10 Part 1: Skin Form and Function

systems as explained above, the integu- can be transferred through bodily fluids, mentary system also contributes to numer- like Hepatitis B and HIV. It is important to ous physiological processes, especially those make sure that tattoo parlors are clean. involved in the regulation of the body’s That means making sure that new and ster- internal environment, to maintain stable ile needles are used, that the ink used is conditions. Examples of the way that the new and not recycled, and that the tat- skin helps in temperature regulation are tooist uses gloves that touch nothing but changes in the pattern of blood supply to the tattoo. The FDA also states that a the skin and sweating. Other examples of machine called an autoclave, which uses physiological process involved in maintain- heat to clean tattooing tools, should be ing stable internal conditions are the regu- on the premises of the tattoo parlor. lation of the amounts of water and miner- als in the body, the inhaling of oxygen, and the exhaling of carbon dioxide.

Tattoos Many people see the skin as more than a protective shield; they also see it as a palette on which to express their thoughts, feelings, and creativity. Tattooing and body piercing are the main methods employed for self-expression on the skin. Some scientists believe that markings found on the world’s oldest mummified human remains, the Iceman, are tattoos. If so, then tattoos have been around for over 5,000 years. Egyptian and Nubian mummies, dated 2000 BC, have also been found to bear tattoos. Considering how long they have been around, the process should seem simple, but people still have a lot of questions— especially about the safety of tattoos.

In order to form a permanent tattoo, the skin must be pierced. A needle is inserted about 1/8 of an inch into the dermis. Unlike the cells in the epidermis, the skin’s outer layer, which constantly shed, the cells of the dermis are stable. This is why once the ink is inserted into the dermis the tattoo is permanent unless a surgeon removes it with lasers, “sanding,” or a knife.

Whenever the skin is pierced, the body is vulnerable to infection from bacteria and other pathogens. Because skin is pierced, blood often touches tattooing tools, which increases risk of exposure to diseases that 11

Part 2: Healthy Skin

A lifetime of skin babies’ skin has a thinner epidermis and a thicker subcutaneous s with the rest of our body, tissue layer than it will as they our skin changes through- grow. Their skin also has more out our lives. This chapter hyaluronic acid, which retains willA look at the way skin changes 1,000 times its weight in water. from infancy to the teen years to Finally, babies also regrow the adulthood. top layer of skin in as little as Babies’ skin two weeks, while the same process can take more than a At birth, a baby’s skin is very month for a middle-aged adult. soft—thus the saying, “as soft as When babies are born, their skin a baby’s bottom.” This is because is usually smooth and puffy.

13 Skin: The Science Inside

Within a few days, the baby’s Some babies do have birth- color will even out, and red marks. These can be tempo- marks, scratches, or bruises rary—such as the salmon patches caused by delivery will go away. (sometimes called “stork bites” or Babies may continue to look “angel kisses”) some light-skinned blotchy because of blood circula- babies have on the back of their tion at the surface of the skin, but necks or the bridge of their noses this is normal. It is also normal or the Mongolian spots found on for their lips, hands, or feet to nearly half of all African- turn a bluish color when they are American, Asian, and Native- cold (but that should go away if American babies. These birth- you move their limbs or move marks are patches of bluish them into a warmer location). stains found on a baby’s back or Their skin may also change color bottom. Other birthmarks are when they cry, or when they have permanent—such as port-wine a bowel movement. All of these stains (large, flat, reddish-purple conditions will go away as they colored lesions) or pigmented get older. nevi (brown or black moles)—that

14 Part 2: Healthy Skin will not go away and that should only. Spending some time not in be watched by a dermatologist as a diaper can also prevent diaper a child grows up. rash from developing. Putting children in disposable diapers, or During the first few days of life, in stay-dry liners inside a cloth babies’ skin will become dry and diaper, may also help prevent the flaky. In fact, the top layer of skin condition. If diaper rash does is shed and replaced during their develop, try to rub the affected first week. area as little as possible, allow the area to dry thoroughly before Infants may also have pale, fine, putting a new diaper on, and use soft hair that covers their fore- a thick layer of ointment or cream head, cheeks, shoulders, and that contains zinc oxide or petro- back. This hair is called lanugo leum jelly to coat the skin in the and develops when a baby is in affected area. If the rash develops the mother’s womb as an insula- blisters or pus-filled sores, or if tion layer. It will fall off sometime it doesn’t go away after three during the baby’s first month. days, contact the child’s doctor.

A baby is also more prone to getting mild skin rashes during the Teenagers’ skin first few months of life. Milia, or As children grow into teenagers, enlarged oil glands, may appear they begin to enter puberty. as little yellow or white dots on During puberty, a teenager’s hor- the chin, cheeks, and nose. mones begin to change his or her Neonatal acne can be caused by body. A girl will grow breasts and maternal hormones passed on begin menstruating. A boy’s voice through breastfeeding. It can be will lower and he will begin to made worse by lying on sheets produce sperm. Both will go cleaned in harsh chemicals or on through growth spurts and devel- bedding that has been spit up on. op underarm and pubic hair. Most teens will develop acne. Babies will occasionally get diaper rash, which occurs when a Some of the same hormones that child’s skin remains in contact for cause the body to change also a long time with wet or soiled cause the body to begin producing diapers. Prevention is the best more oil in the skin. This oil can method for treating this condi- clog pores, causing acne. Oil pro- tion: change a baby’s diaper often duction begins to slow as we age, and rinse the baby with water and most teens will find acne 15 Skin: The Science Inside

becomes less of a problem as they This artwork shows a cross-section of healthy young skin with its regular arrangement of head toward their twenties. collagen fibers (brown). The collagen sup- Although adults also can have ports the dermis (the middle layer, in pink), acne outbreaks, they are usually giving it tone and strength. In elderly skin, the fibers break down, leading to wrinkles. less frequent and less severe by the early 30s.

We will talk more about acne in the next section, “Skin Disorders and Treatment.” The discussion of acne begins on page 28.

Adults’ skin

As adults grow older, their skin ages both from the inside and from the outside.

Within our skin, collagen production slows and elastin becomes less resilient. New skin cells are produced less quickly, and dead skin cells are not shed as often. These changes begin in our 20s, but are 16 Part 2: Healthy Skin not usually noticeable until our because of sun exposure, depends 40s. These changes can be directly upon a person’s skin color delayed by using sunscreen with (lighter skin tones are more at SPF 30 or higher or moisturizers. risk) and the person’s history of In addition, regular cleansing and sun exposure (the more time you use of topical anti-aging moistur- spent in the sun, particularly at izers can help to reduce the its most intense, the more likely appearance of aging. you are to suffer ill effects through photodamage). The sun’s Our skin also has a harder time UV light damages elastin, making preventing moisture loss as we the skin less stretchy, which may age because the production of contribute to forming wrinkles. sebum or oil from the sebaceous The skin surface may become glands slows over time. This can rough and leathery, and darker cause dry skin, particularly on spots or freckles may appear. our extremities. The changes the skin goes Signs your skin is aging include: through due to this process can • Wrinkles include: • Thinner and more transparent • Freckles skin • Age spots or “liver spots” • Hollows in the cheeks and eye • Spider veins on the face sockets and looser flesh on the • Rough or leathery skin neck and hands, due to a loss or • Wrinkles redistribution of fat in the subcutaneous tissue • Blotchy complexion • More prominent veins and bones • Precancerous growths • Dry skin • Skin cancer • Slow healing when injured We will talk more about sun exposure and skin cancer in External skin aging is more with- Part 4, which begins on page 31. in our control, but still not entire- ly so. While we can control how Other things that contribute to much sun exposure we get (the external skin aging include smok- number one cause of premature ing, sleeping in the same position aging), we cannot control gravity. every night (for those who sleep on their sides or stomachs), facial Photoaging, or the amount of expressions, and gravity (particu- aging your skin undergoes larly as we reach our 50s). 17 Skin: The Science Inside

Skin ages, just as the rest of one’s body does. Spending time in the sun can speed along the process. Signs of external skin aging include liver spots, wrinkles, and rough or leathery skin.

18 Part 2: Healthy Skin

Healthy Hair and Nails helps to retain pheromones, or chemicals secreted by the body Hair and nails consist predomi- to attract a mate, but there is no nantly of keratin just like skin. proof this is the case with humans. Hair Hair serves as an extra layer to As mentioned in the first chapter, keep us warm—about 90% of our hair grows out of follicles located body’s heat is lost through the in the skin, and is found every- head. Nose hair, eyebrows, eye- where but on our palms, soles, lashes, and the hair in your ears and lips. Each hair consists of a help keep dust and other parti- hair shaft (the part above the cles from getting into sensitive skin) and root, which ends in a areas. Eyebrows and eyelashes bulb that sits in a follicle. Each also help protect our eyes by fil- hair has three layers: the cuticle, tering light before it reaches or outside protective layer, that them. There is some question is covered with a protein called about the purpose that pubic and keratin; the cortex, or main underarm hair serve. Studies of layer, where the pigment is animals (including other pri- found; and the medulla, or soft mates) suggest that this hair center layer.

19 Skin: The Science Inside

The root, the part of the hair that Nails is located below the surface of the Nails exist to protect the sensitive skin, is alive. The hair shaft itself tips of your fingers and tops of is no longer alive and does not your toes from injury, as well as receive any nourishment. providing structure to those areas. They also help us pick up small Hair grows approximately 1/4 of items and serve as a way for us to an inch every month and, in its protect ourselves. active growing phase, will continue to grow for two to six years before Nails grow from the matrix, it falls out and is replaced by a which is the root of the nail and new hair. Hair follicles determine which lies below the skin-nail fold the width of each hair—thick hairs called the cuticle. Cells from the grow out of bigger follicles and epidermis just below the matrix thinner hairs grow out of smaller slowly move up to the surface of follicles. As you age, fewer hairs the skin. Because of the matrix, grow as follicles start to become cells at the tips of your fingers and inactive and the hair goes gray. toes get crushed tightly together Follicles that die no longer produce and form into layers, pushing your hair, which can lead to baldness. nail forward. Nails above the cuticle are not alive and are made of Baldness, or alopecia, can result keratin, just like your hair. from a stress to the body, such as illness, chemotherapy, or severe The half-circle at the base of each burns. Typical baldness seen in nail is called the lunula. It is part some men (called male pattern of the nail plate. White spots may baldness) is passed down through develop on fingernails indicating a person’s genes and cannot be a temporary change in the rate the prevented. Medication may slow nail is growing. hair loss, and surgery can trans- plant healthy hair follicles to Fingernails grow 1/8 of an inch a replace dead ones. month, three to four times faster than toenails. Nails will continue Some people believe that if they to grow back if torn off as long as shave hair off, their hair is more the matrix isn’t damaged. As you likely to grow back thicker. This age, nails grow more slowly, belief just isn’t true. A new hair become brittle, and sometimes growing out of the skin may thicken. appear thicker for a short period of time, but that’s just an optical 20 illusion. Part 2: Healthy Skin

When changes in your nail mean more

SPOON NAILS: If your nails are soft and con- cave, this may be a sign of anemia, a defi- ciency of iron in the body

YELLOW NAIL SYNDROME: Slow growth of the nail allows the nails to thicken and turn green or yellow. This may be a sign of a respiratory condition, like bronchitis, or of swelling of the hands. TERRY’S NAILS: If your nails look opaque, but have a darker band just below the fingertip, this could be just a sign of aging, but is also a symptom of cancer, congestive heart failure, liver disease, and diabetes.

BEAU’S LINES: If your nails have a horizon- tal line running across them, it means that a serious illness, such as a heart PITTING: Small pockmarks that appear in attack, interrupted your nails may be a sign of psoriasis. the growth at the matrix. It is also a sign of malnutrition.

CLUBBING: When the tips of your fingers ONYCHOLYSIS: When your fingernails get larger and your fingernails curve become loose and separate from the bed, it around your fingertips, this may indicate may be a sign of something minor like an lung or liver disease. This can also be injury or a reaction to a nail hardener or genetic. acrylic nails, but also could signify thyroid disease, fungal disease, drug reactions, or psoriasis.

Part 3: Skin Disorders and Treatment

e tend to pay attention to our skin most when there is something wrong with it—when it itches, Wwhen it turns an odd color, when it breaks out in some way. And this happens frequently, if the 11.8 million times a year Americans visit a doctor because of skin rashes is any indication. This section of the book will talk more about the problems we can have with our skin.

Skin Allergies An allergy is the body’s overreaction to certain substances, called allergens. An allergic person responds differently to allergens than does a person with no allergies. A person with allergies should avoid allergens that are known to cause symptoms. People who have experienced severe allergic reactions should be under the care of an allergist—a physician who specializes in the treatment of allergies.

When a person is having an allergic reaction to something, cells located in the nose, eyes, lungs, and gastrointestinal tract release chemicals called histamines. These chemicals are responsible for producing the symptoms of the allergic reaction—runny nose, watery eyes, or itchy skin, for instance. Inflamed tissues might 23 Skin: The Science Inside

grow more inflamed as these ally starts showing up when a per- chemicals draw other swollen cells son is a baby, it can develop later to the area. Medicines called anti- on, particularly among people with histamines can be given to pre- hay fever. A red, scaly, itchy rash, vent histamines from taking eczema usually affects the face effect. and behind the elbows and knees. The rash will sometimes ooze and Allergies are not contagious. sometimes will be very dry.

Common triggers include over- Eczema heating or sweating; contact with Eczema is the common name for irritants such as wool, pets, or atopic dermatitis. While it gener- soaps; emotional stress; certain foods; and secondary staph infec- African American skin and moisture tions. To prevent the rash from itching, patients should remove Dry skin does not discriminate, but it is more noticeable in some people. African Americans, and others with dark skin, the irritants and may want to may find that they suffer from dry skin flaking that appears use a corticosteroid cream. gray or ashy against their complexion. Prolonged scratching will make A warm (not hot) bath with some ground-up oatmeal the rash worse. added to it may relieve some of the discomfort associated with ashy skin and may be effective at helping the skin retain moisture. Using moisturizers can help, but be sure to choose a prod- Contact dermatitis uct that is designed not to clog pores (non-comedogenic Contact is a red, itchy moisturizers). Pomades may make a scalp less dry, but if dermatitis they come into contact with your forehead, they may also rash caused by an irritant coming lead to a bacterial infection called folliculitis that can into contact with the skin. There cause hair loss. If you start to notice red or bumpy skin, are two kinds: contact a dermatologist. • Allergic contact dermatitis occurs only where an allergen touches the skin, and tends to flare up after touching a plant such as poison ivy or poison oak. Allergic reactions can occur one to two days after coming into contact with the irritant and will take 14 to 28 days to totally clear up. In addition to the common poisonous plants that cause this reaction, irritants may also 24 Part 3: Skin Disorders and Treatment

include nickel, perfumes and fragrances, dyes, latex, and certain cosmetic ingredients, as well as some medications. Corticosteroid creams may help relieve the itching if only a small part of the body is affected; a corticosteroid pill may be prescribed if the rash is over a large part of the body. To prevent a reaction from recurring, avoid contact with the irritant. • Irritant contact dermatitis is more often painful, instead of itchy, the way allergic contact The science of allergies dermatitis is. It is caused by an A person with allergies has an immune system that irritant actually damaging the overreacts to substances that do not produce symp- skin where it comes into con- toms in most people. Substances that are otherwise tact with it. The longer the irri- harmless, such as animal dander or dust, can trigger a severe allergic reaction in a person who is sensitive to tant touches the skin, the them. worse the reaction will be. Because water with added A healthy immune system would normally ignore these substances. But for those people who are aller- soaps and detergent is the most gic to them, their immune system believes that the common cause, this rash gener- substance is an invader that must be fought off. ally appears on the hands. Scientists do not know why some substances are allergens for some people and harmless for others. People with eczema are particularly at risk for this rash. A person can be allergic only to something to which People with this problem he or she has been exposed. The first time an allergen enters the body of a person who is likely to should take care to avoid develop allergies, a certain type of allergen-specific whatever causes the reaction. antibody is produced. This antibody travels to cells in certain areas of the body and waits for an invasion by a particular allergen. If the allergen does enter the Hives body, the antibody will capture it and the cells where the antibody have been staying release chemicals Hives are red, itchy, raised welts such as histamine. These chemicals are responsible for producing the symptoms of an allergic reaction. that appear on the face or body. They are usually caused by an The exact cause of allergic reactions is not known. allergic reaction, most frequently However, there does appear to be a hereditary com- ponent to the more common allergies. to a virus, drugs, food, or latex.

25 Skin: The Science Inside

Eczema rash on the back of a sixteen- Common causes of skin month-old girl. The rash is across her shoulders where she is scratching and irritations and allergies the lower right side of her back. include: • Poison ivy, sumac, and oak • Metals, including nickel or nickel alloys; cobalt; chromate; and gold • Latex or rubber • Acrylates (found in artificial nails, nail repair kits, eyeglass frames, and dental resins) • Hair dyes • Pine resin or colophony (found in some mascaras, among other things) • Bee, wasp, and hornet stings • Mosquito, flea, and mite bites • Fragrances and preservatives in cosmetics and skin care products • Herbal remedies containing certain plants

Immune system connection Skin is more than just a way to keep our While mild cases of hives can be organs in place. It acts as the first barrier against disease and infection, forming a treated with an antihistamine, seal against harmful agents. When hives may be a sign of a deeper swelling, bumps, and inflammation of the allergy to something and can be a skin occur, this is often a sign that the skin has been opened in some way and that an symptom of anaphylaxis, a severe infection has gotten into the body. allergic reaction which can quickly Mosquito bumps, for example, are the lead to death if left untreated. body’s reaction to the saliva that a mosquito leaves in the blood. Many of the Other symptoms include fever, skin’s reactions, such as itching, swelling, difficulty swallowing or breathing, and bumps, are a result of some sort of nausea, vomiting, diarrhea, bacteria or other irritant entering the body. abdominal or uterine cramping, congestion, swelling, a feeling of Along with acting as a defensive barrier, having to urinate, swelling of the the skin also has some weapons of its own. The epidermis uses Langerhans cells lips or joints, severe anxiety, to trap antigens and transport them to headache, itching, sneezing, cough- the lymph nodes where white blood cells ing, or wheezing. The most danger- fight infection. ous symptoms are low blood pressure, breathing difficulties, 26 Part 3: Skin Disorders and Treatment shock, and loss of consciousness. scaly or flaky rash shows up over Anaphylaxis should be treated red, irritated skin. The red skin with an injection of epineph- comes from the increased blood rine, a chemical form of the flow needed to feed the reproduc- hormone adrenaline, in addition ing cells, while the white rash is to antihistamines and steroids, the dead skin cells, which are and the person should be taken piling up faster than they nor- to the hospital as soon as possi- mally would. ble. (You should never drive yourself if you think there is even a A lifelong disease that affects possibility you are suffering from 4.5 million Americans, psoriasis anaphylaxis, because you could has an unpredictable cycle of pass out while you are driving flare-ups, improvement, remis- and cause an accident.) The soon- sion, and recurrence. Triggers er the person is treated, the less for flare-ups include emotional severe the symptoms stress, injury to the skin, some will be. types of infection and reactions to certain drugs, and may also Hives are common, affecting include weather, diet, and nearly a quarter of the U.S. allergies. population sometime during their lives. Psoriasis can affect the whole body, but generally is found on the knees, scalp, elbows, and Psoriasis torso. Psoriasis is not actually a skin disease; it’s actually a disease of the immune system. The cause is not well understood. It is charac- terized by skin cells that reproduce much faster than they are supposed to—every three to four days instead of every 28 to 30 days—and that fail to shed properly.

As a result, the outermost layer of skin thickens because of the increased schedule of cell building, and, on the surface, a white 27 Skin: The Science Inside

In addition, 10–30% of those The blemishes of acne can be affected by psoriasis also suffer divided into five main types: from psoriatic arthritis, where Blackheads occur when the hair their joints are inflamed, as well follicle is partly blocked on the as their skin. Neither condition is surface of the skin. The top sur- contagious. face darkens. While there is no cure for psoria- Whiteheads occur when the hair sis, there are treatments to help follicle is totally blocked. They calm outbreaks. These include bulge out from the skin. shampoos, creams, light therapy, Pustules are raised red pimples and drugs (given as pills or shots). or blocked pores with pus present Small amounts of sun exposure in the center. may help to clear flare-ups, but sunscreen should be used every- Papules are red inflamed tender where the psoriasis hasn’t bumps that do not seem to have a affected. head. Nodules or cysts occur when the wall of a plugged hair follicle Acne breaks deep in the skin. These Acne occurs when the skin’s hair pus-filled lumps are larger than follicles become blocked by dead pimples and can be quite painful. skin cells that have not shed properly but have become sticky with While acne is most common sebum. When this happens, the oil amongst teenagers, it may contin- that usually travels freely up to ue into the early 30s. Some people the surface of the skin along the may suffer from acne outbreaks hair follicles is blocked. Once the even into their 50s. follicles are plugged, bacteria can grow, causing infections and It should be noted that acne is not inflammation. the same as rosacea, which is sometimes incorrectly referred to Scientists do not know the exact as adult acne. Rosacea is a sepa- cause of acne, but believe it to rate skin disorder that is charac- result from a combination of fac- terized by persistent redness in tors, including hormonal fluctua- the center of the face. Rosacea has tions, genetics, the use of certain no cure, but can be treated drugs, and exposure to certain through a combination of diet compounds. modification (such as avoiding hot drinks, caffeine, alcohol, and spicy 28 foods) and medication. Part 3: Skin Disorders and Treatment

Some myths persist when it To help prevent acne, clean the comes to acne. It is not true that skin gently with a mild cleanser bad acne means bad personal and warm (not hot) water and hygiene. Sweating also does not rinse thoroughly; shampoo regu- cause acne, nor does chocolate. larly; avoid rubbing, touching, or Acne can be worsened, however, picking at skin irritations; shave by picking at blemishes; oil-based facial hair carefully; avoid sun- makeup, suntan oil, hair gels, and burns or suntans, particularly hairspray; hormonal fluctuations, if you are taking an anti-acne such as a menstrual period; con- medicine that increases your tact with oil and grease from hair, sensitivity to the sun; and use cooking oils, or the environment; only oil-free cosmetics. and hard scrubbing of the skin.

Artwork showing the formation of acne. A hair follicle and its sebaceous gland (pale yellow) are seen in the skin. The sebaceous gland produces sebum, an oily substance which waterproofs the hair (seen at left) and is especially active during adolescence. If the hair follicle becomes blocked (center), the sebum builds up in the follicle, leading to an acne spot, or whitehead (right).

29 Skin: The Science Inside

Psychological/sociological require light therapy, chemical peels, drainage, injections, or surgery by a effects of acne dermatologist. They may also be treated with prescription medicines, including Acne usually develops at birth control pills (for women only), certain the onset of puberty, due oral antibiotics, or medicated creams. to hormonal changes. There is a lot of debate The FDA recognizes these ingredients as about the ultimate cause safe and effective for the treatment of acne of acne, but there is no in over-the-counter skin care products: doubt that having it can • Benzoyl peroxide make you feel less confi- • Resorcinol and sulfur combination dent about yourself. • Salicylic acid Because the condition • Sulfur or sulfur-based drugs of their skin is one of the first things that we It should be noted that benzoyl peroxide notice about someone and salicylic acid can be used to help pre- else, conditions that vent future outbreaks. Products containing affect the skin often have these ingredients should be applied to the social and psychological entire face or body, not just to the pimple impacts. Acne is one of to get maximum benefit. those conditions that we As with all treatments, there are no quick spend a lot of time think- fixes. While improvements in acne can be ing and worrying about. seen very quickly, weeks are generally It can make us feel bad required before maximum results will about ourselves, so bad that we choose to be seen. be alone rather than to be in places where people can see it. People with acne often try to hide from the world, at a time when it is most important to learn how to inter- act with those around them. About 85% of the population between the ages of 12 and 25 develops acne. Yet, despite the fact that it is a problem that most people have to endure, many acne sufferers feel as if they are alone.

Healthy options for making acne less noticeable

Despite the fact that acne is a common problem, no one really wants to live with blemishes if they don’t have to. Luckily, there are some healthy options for treating acne and for making it less noticeable. For mild acne, washing the affected area twice a day and using an over-the-counter cream with benzoyl peroxide or salicylic acid may help. More severe cases may

30 Part 4: Sun Exposure and Skin Cancer

Sun and your skin he sun gives life. In addition to warming and light- ing the earth, it also helps plants,T the bottom rung of the food chain, to grow. Additionally, there is research that suggests exposure to sunlight may help reduce depression, particularly during the winter months.

Sunlight is the source of ultraviolet rays, which can be divided Sometimes the UV exposure can into two types, Ultraviolet A cause a defect in the DNA of a (UVA) and Ultraviolet B (UVB). cell. When that happens, it will UVB rays help the body produce keep on dividing and copying the and process vitamin D, which is error in the DNA into future ver- necessary for strong bones. sions of itself. The new cells may divide and grow wildly, becoming Unfortunately, UV rays also are a skin cancer. responsible for suntans, sunburns, and premature aging. Melanin, or the pigment in the They also cause skin cancer skin, absorbs radiation from UV and eye damage. rays. Therefore, it acts as a sunscreen to the cells below it. UVA rays penetrate more deeply People with dark skin have a lot into the skin and are partially of melanin in their skin natural- able to penetrate through even ly. Lighter-skinned people must heavy clouds, glass, and smog. produce extra, which is why they tan and burn when exposed to a Ultraviolet exposure over time lot of sun. However, no matter can cause the destruction of indi- how much melanin you have in vidual cells in the skin and eyes. your skin, it is not enough to 31 Skin: The Science Inside

A guide to sunscreen screen out all the UV rays, and some will damage your skin. You Sunscreens are important to use on a can help limit the damage by regular basis. Here are a few things to keep in mind about them: using sunscreen. • The chemicals in sunscreen that absorb UV rays need approximately 20–30 minutes to seep into your skin. Apply it at What is skin cancer? least 20–30 minutes before you are planning to be in the sun. Sun damage to your skin can • Unless it is labeled as “broad-spec- cause the skin’s cells to change trum,” a sunscreen will best protect against UVB rays, not against UVA rays. and grow out of control—a condi- • SPF stands for “Sun Protection Factor.” tion known as skin cancer. Catch- The higher the number, the better. ing the cancer early is a key to • Doctors recommend a sunscreen with treating it, so you should perform an SPF of 30 or higher at all times. regular checkups of your skin to • Reapply sunscreen frequently; every 90 make sure it hasn’t changed. Skin minutes is a good timeframe. is damaged below the surface for • Even waterproof sunscreen will wash off over time. Don’t forget to reapply. a long time before the problems • Cloudy skies do not completely stop UV make their way to the surface, so rays from reaching the ground. you shouldn’t delay if you notice Therefore, wear a sunscreen even on something wrong. cloudy days.

There are three types of skin cancer: • Basal cell carcinoma • Squamous cell carcinoma • Melanoma

Basal cell carcinoma is the most common form of skin cancer and of cancer, in general. It is slow growing (it may grow only one to two centimeters over several years’ time) and usually does not spread far or fast. Early treatment offers excellent recovery rates.

Basal cell carcinoma grows in the basal cells, which are at the bottom of the epidermis. It is a result 32 of chronic exposure to sunlight, so Part 4: Sun Exposure and Skin Cancer it is most commonly found on tight. This symptom can be the exposed parts of the body—the sign of an aggressive tumor. face, ears, neck, shoulders, and back—and on the scalp. On rare Two or more of these characteris- occasions, tumors will grow on tics are often found in one tumor. unexposed areas, on areas that In rare cases, though, basal cell have come into contact with carcinoma resembles another arsenic or radiation, or on the site skin condition. It is best to give of old burns, scars, vaccinations, yourself regular self-exams (espe- or tattoos. cially if you have a skin condition) and to see a skin doctor The most common characteristics regularly. of a basal cell carcinoma are: • An open sore that oozes, bleeds, Until recently, this type of skin or crusts over and refuses to cancer mostly affected older peo- heal for three or more weeks. ple, particularly men who had This is the most common worked outside. But now, 800,000 symptom. Americans are affected by basal cell carcinoma every year and are • A reddish patch or irritated area that may crust over, itch, or hurt. This is most frequently What is cancer? found on the chest, shoulders, Cancer is a large group of diseases that are caused by arms, or legs. abnormal cells growing out-of-control. These cells grow • A shiny bump or nodule that is and divide into new cells very rapidly, and eventually they move into and infect new areas of the body. pearly or translucent. Although Cancer is caused by damage to the DNA in cells. While usually pink, white, or red in the body is normally able to fix damaged DNA, for some color, the bump can also be reason, cancerous cells’ DNA is unable to be repaired. darker, particularly in those Most cancers (although not all) begin as tumors or with darker coloring. growths. Tumors that are malignant are ones that spread and that eventually can be fatal. Benign tumors do not • A pink growth with a slightly spread and generally are not considered dangerous. raised rolled border and a crust- Cancers are treated differently depending on what kind ed over indentation in the mid- they are. Skin cancer is treated differently than lung dle. Blood vessels may appear cancer or other types of internal cancers. on the surface over time. While doctors nowadays believe that you are never cured •A scar-like wound, scab, or spot of cancer, they do believe it can be treated so it does not come back. Remission rates depend on how early in an area that hasn’t been you detect the disease and how aggressive it is, so going injured. Generally the scar-like to the doctor as soon as you notice a problem is very area is white, yellow, or waxy important. and has vague borders. The 33 skin of the scar looks shiny and Skin: The Science Inside

being diagnosed younger and younger. More women are getting the disease than in the past, but this skin cancer is still more common among men.

Squamous cell carcinoma is the second most common type of skin cancer. It is not as slow growing as basal cell carcinoma, but is not as aggressive as melanoma. It will eventually spread to other areas of the body. Basal cell carcinoma

Squamous cell carcinoma grows in inflammation or a suppressed the squamous cells that are in the immune system. middle layers of the epidermis. It is mostly found on parts of the Symptoms of a squamous cell body that get sun exposure and carcinoma: frequently targets the lower lip • A wart-like growth that crusts and the rim of the ear, but it can over and bleeds. occur anywhere on the body, including the mucous membranes. • A persistent, scaly red patch with This type of skin cancer also can irregular borders that sometimes occur anywhere the skin has suf- crusts over or bleeds. fered an injury or been exposed to • An open sore that bleeds and X-rays or chemicals, as well as in crusts over and refuses to heal. those who have a chronic skin • A cone-like growth. • A raised growth with a depression in the middle that sometimes bleeds. This type of growth may grow quickly.

Squamous cell carcinoma affects Squamous cell more than 200,000 Americans a carcinoma year. While dark-skinned African Americans are less likely to develop skin cancer, 2/3 of their skin cancer cases are squamous cell 34 carcinoma, usually on the site of a Part 4: Sun Exposure and Skin Cancer previous burn injury or inflamma- lymph nodes, if you notice symp- tory skin condition. This type of toms, you should call your doctor skin cancer is more common immediately. among people over the age of 50. Melanoma is a cancerous tumor People should pay attention to that originates in melanocytes, certain signs because they mean the cells that produce the pigment a person is at higher risk to devel- that colors our skin, hair, and op this type of skin cancer: eyes. Because of this, most •Actinic or solar keratosis: these melanomas are brown or black are rough, scaly, slightly raised (although some may stop produc- growths that appear mostly on ing pigment and may be skin-col- older people. ored, pink, red, or purple). It is directly related to sun exposure, •Actinic cheilitis: a type of actinic particularly severe sunburns dur- keratosis that occurs on the lips ing childhood. It is most common that causes them to become dry, among people with fair skin, light cracked, scaly, and pale or eyes, and red or blond hair. white. •Leukoplakia: white patches on There are four main types of the tongue or inside of the melanoma: mouth. • Superficial spreading melanoma •Bowen’s disease: a persistent travels along the top layer of red-brown scaly patch that may skin and is usually flat or only resemble psoriasis or eczema. slightly raised. Irregular in shape, the patch has varying Squamous cell carcinoma has a shades of black, brown, tan, red, high cure rate if it is caught before it spreads to other parts of the body.

Melanoma is the most serious and the most deadly form of skin cancer. That said, if it is caught early and removed while it is still thin and limited to the epidermis, it is almost always curable. Because this cancer spreads quickly and is difficult to treat once it spreads past the skin and Melanoma 35 Skin: The Science Inside

blue, or white. Sometimes an nails, on the palms or on the older mole will change color or soles of the feet. It is the most shape in this way. It is the most common melanoma among common type of melanoma and African Americans, Asians and affects mostly Caucasians. It others with dark skin. It is least can occur at any age and any- common among Caucasians. where on the body, but is most likely to occur on the trunk in During the last 10 years, the men, the legs in women, and the number of cases of melanoma upper back of both. has increased more than any • Lentigo maligna melanoma also other type of cancer, with 51,000 remains close to the skin’s sur- new cases every year. In the face for quite a while. It usually United States, one in 85 people appears as large areas of flat or will develop melanoma at some slightly elevated mottled tan, point during their lives. Mela- brown, or dark brown color. It is noma is the top cause of cancer most common in the elderly. It death in women between the ages occurs where the skin has been of 25 and 30. weathered by the sun—particularly on the face, ears, neck, You are most at risk for melano- arms, and upper trunk. ma if you: • have a family history of the • Nodular melanoma is the most disease; aggressive kind of skin cancer because it penetrates the skin • have light hair or skin; and moves to other parts of the • have multiple birthmarks; body quickly. It is generally a • develop a precancerous growth black bump or raised area, but (actinic keratosis); can be blue, gray, white, brown, • have freckling on the upper tan, red, or skin-colored. It gen- back; erally is found on the trunk, • have three or more blistering legs, and arms, usually of older sunburns before you turn 20; people, as well as on men’s scalps. • work at an outdoor job for three or more summers as a • Acral lentiginous melanoma is teenager; or the least common form of skin • have high levels of exposure cancer. It also spreads along the to strong sunlight. surface of the skin, but generally appears as a black or brown discoloration under or along the 36 Part 4: Sun Exposure and Skin Cancer

Generally, if you have warts, moles or other skin growths, you should check them regularly and contact a doctor if they change shape, size, texture, or appearance or if they begin to hurt, swell, bleed, or itch.

Recognizing melanomas early is the only way to survive them. If you notice any of the following four ABCD symptoms, contact a doctor immediately: Borders • Asymmetry: the two halves of the abnormal area are different from each other. • Borders: the growth is oddly shaped. • Color: the color of the growth varies or is mixed. • Diameter: the spot is bigger than a pencil eraser.

Color

Asymmetry Diameter 37

Part 5: Promising Research: The Skin Care of Tomorrow

he thing to remember about skin cancer and skin conditions is that while they can beT scary or intimidating when you’re first diagnosed with them, scientists are working hard to improve prevention and diagnosis and to find treatments and cures for all of them.

Here’s a look at some of the research on the horizon: ing outward toward the skin’s The basics of skin surface, where it is eventually growth shed. By understanding this process, scientists expect to figure Scientists are figuring out how out at what point skin diseases skin forms in order to perform all begin to form and why. of its various jobs. Using mouse embryos, they have found that the epidermis starts as a single layer The genetics of skin of cells attached to a membrane of diseases proteins. The membrane commu- nicates with the cells to separate One doctor is attacking skin dis- them from other tissue below. eases through a variety of studies Each cell divides into two new into the genetics of inflammatory, cells, with the one in charge of or autoimmune, skin disorders. cell growth staying attached to She is using the most current the membrane and the other cell, molecular techniques to find and which can be involved in the examine the genes that cause skin’s other jobs, gradually mov- ailments ranging from atopic 39 Skin: The Science Inside

force the skin temporarily, such as with an allergen-blocking cream or ointment, in order to let the skin heal thoroughly and reproduce its normal barrier to the world.

Psoriasis Several recent studies indicate there is a glimmer of hope when dealing with psoriasis. Research- ers have found there is a link between a person’s susceptibility dermatitis and psoriasis to lupus to psoriasis and to atopic dermati- and the hair-loss disease alope- tis. The same study found that the cia. She is using a new technology presence of a certain gene indicat- called “gene chips” to screen for ed whether someone who had thousands of genetic sequences at psoriasis was at risk of developing once. Ultimately, her goal is to dis- psoriatic arthritis. cover what makes people susceptible to these diseases in order to Other researchers are also looking find out who is most at risk and at the genetics of the disease. One how, eventually, to treat their group has discovered that a gene cases. that regulates growth in the vascular system may add to one’s sus- Researchers at the National ceptibility to psoriasis. This find- Institutes of Health recently dis- ing may eventually lead to a new covered that overproduction of a approach to treating the illness. specific protein that helps link Another group is using a genealog- cells to one another causes the ical database, genetic material, skin (or another tissue, like in the and clinical information from nose and lungs) to stop being such patients to better understand the a protective barrier. This can allow role genes play in the development allergens to enter the body, caus- of the disease. Learning how the ing a variety of illnesses—from psoriasis begins and progresses asthma to eczema—and triggering can help doctors prevent it or treat inflammation that again reduces it at its earliest stages as well as the skin’s effectiveness. The dis- figure out who is at risk for devel- covery of this cycle will allow oping it. scientists to look at ways to rein- 40 Part 5: Promising Research: The Skin Care of Tomorrow

Another group of scientists is studying psoriasis at the molecular level. They are working out how a molecule helps cause the painful lesions associated with the illness. Their research also focus- es on the link between this molecule and the immune system malfunction that causes psoriasis.

Meanwhile, a group of researchers is using psoriasis as a model to identify the substances found in the body that trigger an im- Allen G. Li, M.D., Ph.D of Oregon Health mune response for autoimmune and Science University is among the scientists diseases. who are advancing psoriasis research.

Finally, scientists are developing effectiveness. Some stop or slow new ways to treat the condition cell growth or spreading. Others through biologics, which are help to reduce inflammation. drugs synthesized from living organisms or their products and used medically. Biologics are being Skin cancer used to target the reactions that Doctors and researchers are also cause psoriasis, to control the con- working on ways to prevent and dition, and to prevent flare-ups. treat skin cancer. Some scientists Patients have found there to be want to find out the causes of skin fewer side effects cancer and how to prevent it from with these new treatments. forming. One scientist, who is looking at the genetics of basal Currently three biologics have cell carcinomas, is trying to find been approved by the FDA to out what role genes play in the treat psoriasis. A fourth is cur- formation of benign and cancerous rently in the third stage of tumors in order to help other clinical trials. researchers develop diagnoses and treatments that can help people Dozens of other drugs—in pills, earlier. Another study being run shots, and creams—as well as by scientists in Tennessee uses light therapies are in the process focused light therapy to remove of being tested for their safety and 41 Skin: The Science Inside

pre-cancerous skin lesions. This is hoping that the new drug will an alternative for someone who increase the number of people who can’t handle other removal proce- survive advanced melanoma. dures, like freezing, or who has Another New York City research multiple areas that need treat- team is injecting cancer patients ment at one time. with drugs that are designed to stimulate the immune system. Other studies focus on treating Their hope is that the immune cancer. One clinical trial in New system will then recognize and York City is trying to find a better destroy melanoma cells. Research- drug treatment than the standard ers in Texas have found that chemotherapy treatment that is injecting interferon, a protein that being used to treat advanced stimulates the immune system to melanomas. Researchers are help fight cancer, directly into a

42 Part 5: Promising Research: The Skin Care of Tomorrow basal cell carcinoma tumor may Acne be as effective as other methods of Researchers also are focusing treating the cancer. Further tests their attention on skin conditions are being done to find out which that are annoying but not life- treatments are best for whom. threatening, such as acne. Additionally, a group of Boston Michigan scientists are attacking scientists has discovered a genetic the problem at a molecular level. abnormality in the cells of some They are exploring the role of melanoma patients. The presence cells and chemicals under the sur- of the gene makes the cancer face of the skin and are evaluat- much harder to treat. Scientists ing new therapies to treat the are hopeful that this discovery condition. Specifically, this group will give them new ideas about of researchers is looking at the targeting the gene in treatments. molecules that attract the inflam- This study may offer up hope to matory cells that cause the skin some people who otherwise would to become red and bumpy. They’re not have good odds of beating also looking at what effect acne their cancer. may have on the skin’s collagen and its ability to repair itself. Still other researchers are looking Finally, they’re exploring a vari- at ways to improve sunscreens. ety of treatment options from a Some want to create sunscreens woman’s use of birth control that feel lighter when you put pills in combination with topical them on to encourage people to agents (which they’ve found to be wear them every day or that are successful) to the use of pulsed in different formulas (a stick as dye laser therapy (which they opposed to a lotion, for instance). found didn’t work). Others are trying to increase sunscreen’s ability to block UV rays— One Pennsylvania researcher is both in how much they block and looking at the role that hormones for how long. Still others are play in causing acne: whether examining how effective certain there are differences in hormone sunblocks are at higher elevations production between those who where the sun is more likely to suffer from acne and those who burn skin more quickly than at don’t and what changes occur in lower attitudes. the skin that result in adult acne. Having found new information

43 Skin: The Science Inside

about the role of enzymes in the take part in clinical trials; these skin that produce hormones in the trials have helped create today’s oil glands, this scientist is now cancer treatments, acne medicines, also collaborating with other and sunscreens. researchers to develop new acne treatments. Treatments don’t work the same for everyone, however, so it is very Still other researchers are finding important to get a wide variety of newer and better ways to prevent people to take part in clinical tri- and treat acne and to reduce the als. Children and teens (with their scarring it can cause. Some create parents’ or guardians’ permission), new and more effective cleansers. adults, men, and women from all Others create treatments for acne races and ethnic groups, lifestyles, that has become inflamed. and ages are needed to participate in order to make sure treatments and preventions work for everyone. The important role As with any medical decision, of volunteers though, you should think about a decision to take part in a clinical Advances in skin care cannot hap- trial before you agree to it. There pen without volunteers. Some peo- are questions to consider in ple share information about their Appendix 2 on page 48. own and their family’s medical conditions. Others donate skin tis- Without volunteers, advances in sue for researchers to work on. skin care—both for healthy skin Still others agree to participate in and for unhealthy skin—are not clinical trials. Clinical trials are possible. Those who help out get research projects involving volun- the satisfaction of knowing their teers. They test medical treat- involvement in clinical trials may ments, medicines, or prevention some day offer new prevention strategies to see how effective they methods or treatment options for will be. A clinical trial usually is the members of their family or only conducted after a drug or community. therapy has been successful in a laboratory setting. Over the years, hundreds of thousands of Americans have volunteered to

44 Conclusion: What You Can Do to Have Healthier Skin

our skin is important to your well-being. Treat it well and it will continue to Yprotect you from danger and from infection. Here are a few tips to keep in mind:

Stay out of the sun. Avoid the hours of direct sunlight: 10 a.m.–3 p.m. The sun is at its strongest at this point and skin is more likely to burn. Remem- ber that harmful UV rays can penetrate clouds, so this is true even on overcast days. Those who live at higher elevations or closer to the equator should pay particular attention to the amount of sun they get, but even those who live at sea level or close to the poles need to be careful.

Use sunscreen. Doctors recommend a sunscreen with an SPF of 30 or higher. Apply the sunscreen 20–30 minutes before you Wear protective clothing. go outside. Reapply sunscreen Wear a hat with a wide brim to every 90 minutes to prevent it keep the sun off your face, scalp, wearing off. Wear sunscreen and neck. Wear sunglasses with even on cloudy days. UV protection to keep your eyes from being damaged. Wear light- 45 Skin: The Science Inside

notice. Make sure you use a mir- ror to see your back and other body parts that might be hard to see.

Keep your skin and hair clean and well moisturized. Skin and hair require regular cleaning to do their job properly. Wash your skin gently with warm water twice a day to remove dead skin cells and excess oil. If you are prone to dry skin, apply lotion while your skin is still damp to seal moisture in. If you are prone to break outs use products on your skin that say they are non-comedogenic. Wash your hair regularly to keep grease from building up. colored clothing to reflect the light and long pants and shirts when Don’t wait to talk to a doctor. possible to protect your skin from Skin conditions and skin cancer exposure to harmful UV rays. are treatable. Waiting to see a doctor about changes in a mole or Do skin self-exams. Your skin birthmark could limit your options can change quickly and subtly for treatment and ultimately could without a lot of notice. The best make it hard to prevent it from way to learn how your skin spreading to other parts of your changes over time is to begin body. Waiting to see a doctor about doing regular self-examinations a skin rash or condition will mean of your skin. Look at all moles it takes longer before you get and birthmarks. Know their size, relief or know how to prevent shape, texture, and color. That future outbreaks. way, if they change, you will

46 Appendix 1: Questions to Ask Your Doctor about Your Skin

1. I’ve never had any problems with my skin. Should I be worried about the future?

2. Should I be concerned about this spot?

3. If I have skin cancer, what kind is it?

4. Someone in my family has had a skin condition. Am I more likely to have it too?

5. How do I know if I have a skin condition?

6. Why are the symptoms of my skin condition worse some days?

7. How can I tell if I have a skin allergy?

8. How soon should I see results from this treatment?

9. Will I grow out of this allergy?

10. Will I grow out of my acne breakouts?

11. During an allergic reaction, how will I know when I should go to the emergency room?

12. How can I manage my condition to prevent flare-ups?

13. Should I change my lifestyle at all?

47 Skin: The Science Inside Appendix 2: Taking Part in Research Studies—Questions to Ask

A research study is a way of finding answers to difficult scientific or health questions. Here are some important questions you should ask of anyone who wants you, or members of your family or community, to be part of a research study:

1. What is the study about? Why are you doing the study? Why do you want to study me or people like me? Who else is being studied? What do you want to get out of the study? What will you do with the results? Have you or others done this type of study ever before? Around here? What did you learn?

2. Who put the study together? Who is running or is in charge of the study? Whose idea was the study? How were people like me part of putting it together? Who are the researchers? Are they doctors or scientists? Who do they work for? Have they done studies like this before? Is the government part of the study? Who else is a part of the study? Who is paying for the study? Who will make money from the results of the study?

3. How can people like me share their ideas as you do the study? How will the study be explained in my community? Who among people like me will look at the study before it starts? 48 Appendix

Who among people like me are you talking to as you do the study? A Community Advisory Board? Who from the study can I go to with ideas, questions, or com- plaints? How will people like me find out about how the study is going?

4. Who is going to be in the study? What kinds of people are you looking for? Why? Are you trying to get minorities into the study? Are you including people younger than 18 years old? How are you finding people for the study? Is transportation or day care provided for people who take part in the study? Do I need to sign anything in order to participate? Will you answer all of my questions before I sign the consent form? Can I quit the study after signing the consent form? If I quit the study, will anything happen to me?

5. What will I get out of the study? What are the benefits? Is payment involved? How will I be paid? Will I get free health care or other services if I participate? For how long? Will I get general health care or psychological care if I participate? For how long?

6. How will I be protected from harm? Do I stand a chance of being harmed in the study? In the future? Does the study protect me from all types of harm attributable to it? If I get harmed, who will take care of me? Who is responsible? If I get harmed in any way, will I get all needed treatment? Who pays for treatment?

7. How will my privacy be protected? Who is going to see the information I give?

49 Skin: The Science Inside

Will my name be used with the information? What happens to the information I gave if I quit the study? Is there a written guarantee of privacy?

8. What do I have to do in the study? When did you start the study? How long will it last? How much of the study have you already done? Have there been any problems so far? Will I get treated the same as everyone else? What kinds of different treatments are offered in the study? Are there both real and fake treatments?

9. What will be left behind after the study is over? What will happen to the information people give? How will it be kept? What are you going to do with the results of the study? How will the public learn about the results? Will results be in places where the public can see them? Are you going to send me a copy of the results? When? What other studies are you planning to do here?

The questions above are from a pamphlet developed by Project LinCS (Linking Communities and Scientists), Community Advisory Board (Durham, N.C.), and Investigators (University of North Carolina Center for Health Promotion and Disease Prevention) in cooperation with the Centers for Disease Control and Prevention, Atlanta, Ga. For copies of this brochure, contact the CDC National Prevention Information Network at 1-800-458-5231.

50 Appendix Appendix 3: Other Skin Conditions

There are other skin conditions we haven’t mentioned earlier in the book, but about which you may be curious. We include some of them here:

ABSCESS An abscess occurs when your skin is injured in some way (an ingrown hair, for instance) and becomes infected. Pus and other infected material develops in or under the skin and can cause an infection to become worse and to spread to other parts of the body. If an abscess is not treated, the infection that has caused it could lead to the skin tissue around the abscess dying. Your doctor can drain the abscess and treat the infection with antibiotics.

ATHLETE’S FOOT Athlete’s foot is a common condition caused by mold-like fungi. The fungus is contagious and prefers damp areas, like showers and locker room floors. The fungus causes the affected areas, usually the soles of your feet and between your toes, to itch and turn red. If your feet are affected and you touch them and then another part of your body (particularly your palms, groin area, or underarms), the infection can move to that part of the body too.

The infection usually can be treated with over-the-counter medicines. To avoid developing the infection, dry your feet with a clean towel after you get them wet, wear beach shoes or flip-flops in public showers, and avoid wearing damp socks.

The fungi that cause athlete’s foot also cause ringworm, which often affects your scalp, and jock itch, which affects the groin area. You can get this on your forehead a lot, too, which little kids commonly do.

51 Skin: The Science Inside

COLD SORE A cold sore, also known as a fever blister, is caused by a herpes virus. (Herpes is a family of viruses. The one that causes cold sores is not the same one that causes the sexually transmitted disease, genital herpes.) The virus causes small and painful blisters or a rash to show up on an infected person’s lips, gums, mouth, and the skin around the mouth. Most people who suffer from cold sores are infected by the herpes virus when they are newborns or as young children. Outbreaks are triggered by a number of causes, including sun exposure, a fever, menstruation, and stress.

The herpes virus is contagious; if you suffer from cold sores, you should be very careful not to affect other people (by sharing infected razors, towels, or other objects or by having oral sex during an outbreak) or to transfer the infection from your mouth to your eyes. Herpes eye infections are one of the leading causes of blindness. The virus is particularly contagious when you can see or feel blisters, but because the virus lives in the nerves of the face, you do not need to be able to see a cold sore to be contagious.

Untreated, the cold sores will go away after a week or two. Antiviral medicines can shorten that time. There is no cure for cold sores.

KELOID A keloid is a raised, reddish scar at the site of a healed injury caused by too much collagen being deposited there. It is most common in those with African and Asian ancestry.

Some keloids can be partially removed, but it is common for them to come back. Most keloids aren’t dangerous to your overall health, but if a person has a lot of keloids, they could eventually affect the person’s mobility.

SCLERODERMA Scleroderma is a symptom of a group of chronic diseases that cause inflammation and pain in the connective tissues of your body. These diseases can cause your body to overproduce collagen, which causes your

52 Appendix skin to thicken, tighten, and harden. This can make it difficult to bend or straighten your fingers.

There are two main types of scleroderma: localized and systemic. The localized version affects only the skin and its related tissue and will not affect your internal organs. Localized scleroderma can go away over time, but it also can be serious and disabling, because the skin conditions caused by it can become permanent. The systemic version affects more parts of your body, including your other organs and can be limited or diffuse. If it is limited, it develops slowly and affects the skin of only a limited area. If it is diffuse, it comes on quickly and will spread and worsen and will affect other parts of your body, including your heart, lungs, and kidneys.

In addition to skin hardening, scleroderma can also cause painful ulcers, poor circulation in the hands and feet, and difficulty swallowing.

Scientists do not know what causes scleroderma. There is no way to prevent or cure the condition.

STRETCH MARKS Stretch marks are skin defects that appear when the skin stretches rapidly, particularly after a person gains or loses a lot of weight or during pregnancy or puberty. These red, glossy streaks on the skin develop when collagen doesn’t form properly.

Stretch marks will fade to white over time and may eventually disap- pear, but otherwise there is no way to treat them.

Resources

American Academy of Dermatology This organization offers consumer health information related to all aspects of skin and dermatology through their news updates, web site, and magazine. They also offer a number of public programs, including free skin cancer screenings, as well as sponsoring a camp for children who suffer from serious skin disorders. P.O. Box 4014 Schaumburg, IL 60168-4014 Phone: (847) 330-0230 www.aad.org

American Burn Association Dedicated to promoting and supporting burn-related research, education, care, rehabilitation, and prevention. 625 N. Michigan Ave., Suite 2550 Chicago, IL 60611 312-642-9260 www.ameriburn.org

American Cancer Society Dedicated to eliminating cancer as a major health problem by preventing cancer, saving lives, and diminishing suffering from cancer through research, education, advocacy, and service. Atlanta, GA 30329 1-800-ACS-2345/TTY: 1-866-228-4327 www.cancer.org

American Osteopathic College of Dermatology Offers a database of various skin ailments as well as additional information about skin. www.aocd.org/skin/

Centers for Disease Control and Prevention Division of Cancer Prevention and Control Conducts, supports, and promotes efforts to prevent cancer and to increase early detection of cancer. 55 Skin: The Science Inside

Division of Cancer Prevention and Control Mail Stop K–64, 4770 Buford Highway, NE Atlanta, GA 30341–3717 1-800-CDC-INFO/TTY: 888-232-6348 FAX: 770-488-4760 www.cdc.gov/cancer/index.htm

ClinicalTrials.gov A web-based resource for finding clinical trials in need of volunteers. www.clinicaltrials.gov

Combined Health Information Database A web-based service that combines resources on health and disease topics from several federal agencies. A service of the National Institutes of Health. chid.nih.gov/simple/simple.html

Healthy People 2010 A nationwide health promotion and disease prevention campaign sponsored by the Department of Health and Human Services. One of the goals of the campaign is to reduce health disparities. Office of Disease Prevention and Health Promotion 200 Independence Avenue, SW, Room 738G Washington, DC 20201 www.healthypeople.gov

MEDLINEplus A comprehensive source of health information provided by the National Library of Medicine. www.nlm.nih.gov/medlineplus/

Herpes Resource Center Increases education public awareness, and support to anyone concerned about herpes. American Social Health Association P.O. Box 13827 Research Triangle Park, NC 27709 919-361-8400 www.ashastd.org/herpes/herpes_overview.cfm

56 Resources

Melanoma.com Offers information about preventing, diagnosing, and treating melanoma. www.melanoma.com National Cancer Institute The Federal Government’s principal agency for cancer research and training. 6116 Executive Boulevard Room 3036A Bethesda, MD 20892-8322 1-800-4-CANCER/TTY: 1-800-332-8615 www.cancer.gov National Center on Minority Health and Health Disparities Promotes the health of racial and ethnic populations through research and education and through support of minority involvement in research careers. Affiliated with the National Institutes of Health. 6707 Democracy Blvd., Suite 800 MSC 5465 Bethesda, MD 20892-5465 301-402-1366/TTY: 301-451-9532 ncmhd.nih.gov National Eczema Association Improves the health and quality of life for individuals with eczema through research, support, and education. 4460 Redwood Highway, Suite 16-D San Rafael, CA 94903-1953 1-800-818-7546/Fax: 415-472-5345 www.nationaleczema.org National Institute of Arthritis and Musculoskeletal and Skin Diseases Supports research into the causes, treatment, and prevention of arthritis and musculoskeletal and skin diseases. National Institutes of Health Bldg. 31, Room 4C02 31 Center Dr. - MSC 2350 Bethesda, MD 20892-2350 301-496-8190/Fax: 301-480-2814 www.niams.nih.gov 57 Skin: The Science Inside

National Psoriasis Foundation Improves the quality of life of people who have psoriasis and psoriatic arthritis by promoting awareness and understanding, ensuring access to treatment and supporting research that will lead to effective management and a cure. 6600 SW 92nd Ave., Suite 300 Portland, OR 97223-7195 800-723-9166/Fax: 503-245-0626 www.psoriasis.org

National Rosacea Foundation Improves the lives of people with rosacea by raising awareness, providing public health information and supporting medical research. 800 S. Northwest Hwy., Suite 200 Barrington, IL 600100 888-NO-BLUSH www.rosacea.org

National Vitiligo Foundation Educates the public about vitiligo and encourages, promotes, and funds increased scientific and clinical research on its cause, treatments and ultimate cure. 76 Garden Rd. Columbus, OH 43214 614-261-8145 www.nvfi.org

Native American Research Centers for Health Research centers that link the Native American community with health research and that work to increase the number of Native American scientists and health professionals. National Institute of General Medical Sciences National Institutes of Health 45 Center Drive MSC 6200 Bethesda, MD 20892-6200 (301) 496-7301 www.nigms.nih.gov

58 Resources

Nevus Outreach, Inc. Offers support and information to those with nevi, improves awareness and education of the condition, and encourages and sponsors research that will lead to effective treatments and a cure. 600 SE Delaware Ave., Suite 200 Bartlesville, OK 74003 877-4-A-NEVUS/Fax: 281-417-4020 www.nevus.org

New York Online Access to Health A searchable health information resource in English and Spanish. www.noah-health.org/index.html

Office for Human Research Protections A source of information on the guidelines and ethics of research studies with humans. Department of Health and Human Services 1101 Wootton Parkway, Suite 200 Rockville, MD 20852 1-866-447-4777/301-496-7005 www.hhs.gov/ohrp

Office of Minority Health Resource Center Serves as a national resource and referral service on minority health issues. Affiliated with the U.S. Department of Health and Human Services. P.O. Box 37337 Washington, D.C. 20013-7337 1-800-444-6472 www.omhrc.gov/omhrc/

Phoenix Society for Burn Survivors Helps anyone affected by the devastation of a burn injury through peer support, education, collaboration, and advocacy. 835 R.W. Berends Dr., S.W. Grand Rapids, MI 49519 800-888-2876/Fax: 616-458-2831 www.phoenix-society.org

59 Skin: The Science Inside

The Skin Cancer Foundation Educates the public and the medical profession about skin cancer, its prevention by means of sun protection, and the need for early detection and prompt, effective treatment. 149 Madison Ave., Suite 901 New York, NY 10016 1-800-SKIN-490 www.skincancer.org

Sunguard Offers teachers and students information about sun safety and skin cancer. www.sunguardman.org

Sunwise Aims to teach the public how to protect themselves from overexposure to the sun through the use of classroom-, school-, and community-based components. U.S. Environmental Protection Agency 1200 Pennsylvania Ave., NW (6205J) Washington, DC 20460 202-343-9591 www.epa.gov/sunwise/

60 Bibliography

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Allrefer Health. “Skin Characteristics in Newborns.” http://health. allrefer.com/health/skin-characteristics-in-newborns-info.html.

American Academy of Dermatology. “Causes of Aging Skin.” http://skincarephysicians.com/agingskinnet/basicfacts.html.

––. “Contact Dermatitis: Sometimes It’s in Your Face.” http://www.aad.org/public/News/NewsReleases/Press+Release+ Archives/Skin+Conditions/FacialContactDermatitis.htm

––. “The Itch That Won’t Quit.” http://www.aad.org/public/News/NewsReleases/Press+Release+ Archives/Skin+Conditions/FowlerMetalItch.htm

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American Academy of Family PhsyiciansPhysicians. “Psoriasis.” http://familydoctor.org/199.xml

American Academy of Pediatrics. Caring for Your Baby and Young Child: Birth to Age 5. New York: Bantam, 1999.

––. “Treating Diaper Rash.” http://www.aap.org/pubed/ZZZ057QVQ7C.htm?&sub_cat=2.

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American Cancer Society. “What Is Cancer?” http://www.cancer.org/docroot/CRI/content/CRI_2_4_1x_What_Is_ Cancer.asp 61 Skin: The Science Inside

Australian Academy of Science. “Sun and Skin—A Dangerous Combination.” http://www.science.org.au/nova/008/008key.htm

Dana-Farber Cancer Institute. “Scientists Identify Novel Gene Driving the Growth and Survival of Melanoma Cells.” https://www.dana-farber.org/abo/news/press/scientists-identify- novel-gene-driving-growth-survival-melanoma-cells.asp

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Mayo Clinic. “Know Your Skin, Hair, and Nails.” http://www.mayoclinic.com/invoke.cfm?id=SN00001.

National Center for Health Statistics. Centers for Disease Control and Prevention. National Ambulatory Medical Care Survey: 2002 Summary. “Dermatological Conditions.” http://www.cdc.gov/nchs/ fastats/skin.htm.

National Institute of Arthritis and Musculoskeletal and Skin Diseases. “New Findings about How Skin Layers Form May Have Implications for Common Skin Diseases.” October 2005. http://www.niams.nih.gov/ne/highlights/spotlight/2005/skin_ layers.html

––. “Questions and Answers about Acne.” http://www.niams.nih.gov/hi/topics/acne/acne.htm

––. “Scientific Advances Show Promise for People with Psoriasis.” May 2005. http://www.niams.nih.gov/ne/highlights/spotlight/2005/genes_psor iasis.htm

National Institutes of Health. “Genetic Finding Suggests Alternative Treatment Strategy for Common, Complex Skin Disorders and Asthma.” April 25, 2006. http://www.nih.gov/news/pr/apr2006/nhgri-25.htm

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National Psoriasis Foundation. “New Drugs in Development.” http://www.psoriasis.org/research/pipeline/chart.php.

––. “Psoriasis Foundation Awards Research Grants.” http://www. psoriasis.org/news/press/2006/20060412_grants.php

Nemours Foundation. “Looking at Your Newborn: What’s Normal.” http://kidshealth.org/parent/pregnancy_newborn/pregnancy/ newborn_variations.html.

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Vanderbilt-Ingram Cancer Center. “Treatment Shines Light on Skin Lesions.” http://www.mc.vanderbilt.edu/vicc/showcontent.php?id=844

Glossary ab•scess: a pus-filled skin infection. bi•op•sy: the removal and examination of a sample of tissue from a living body. ac•ne: a skin condition that arises when hair follicles become clogged birth•mark: a mole or blemish present with dead skin cells and oil. on the skin from birth. al•ler•gen: any substance that causes black•head: type of acne where the an allergic reaction in susceptible hair follicle is partly blocked. people. blis•ter: a swelling of the skin al•ler•gy: the body’s overreaction to that contains watery fluid and is caused certain substances, such as medications, by burning or irritation. foods, animals, and plants. blood ves•sel: the pipeline through al•o•pe•ci•a: loss of hair; baldness. which blood travels to all parts of the body. an•a•phy•lax•is: a sudden, severe allergic reaction that can have a variety can•cer: a disease in which the body’s of symptoms which can involve major own cells start to grow and divide in an areas of the body at the same time, such out-of-control manner. Left untreated, as the skin, the respiratory system, the cancer cells can spread and shut down gastrointestinal tract, and the cardio- the body’s functions. vascular system. Anaphylaxis can be car•ci•no•ma: an aggressive form of fatal if not properly treated. skin cancer that can attack basal cells an•ti•bi•ot•ic: a drug that kills or squamous cells. bacteria. car•o•tene: a yellow-colored pigment an•ti•bod•y: disease-fighting agent in the skin’s dermis. in the blood. cell: the smallest unit of production in a an•ti•his•ta•mine: a medication that living thing. prevents a histamine—a chemical that chron•ic: long-lasting and ongoing. the body produces during an allergic reaction—from taking effect. clin•i•cal tri•als: research tests performed using people. Trials deter- ap•o•crine glands: glands that mine the success of a medical treatment, develop during puberty and produce medicine, or prevention strategy. sweat during times of stress or high A clinical trial usually is conducted only emotion. after the test has been successful in the ath•lete’s foot: a contagious fungal laboratory and on animals. infection that usually affects the feet. cold sore: a small blister on the lips or bac•te•ri•a: tiny organisms that face caused by the herpes simplex virus. survive on living and nonliving surfaces, col•la•gen: a protein found in the performing many chemical functions. connective tissues of skin. Some bacteria cause diseases in people. con•ta•gious: transmitted from one ba•sal cell: a type of cell found in the person to another by direct or indirect deepest layer of the epidermis. contact. bi•o•log•ics: drugs made from living cor•tex: the middle layer of hair. organisms. 65 Skin: The Science Inside

cor•ti•co•ster•oids: also known as hair fol•li•cle: the pit that encloses the steroids, these strong medications are root of the hair. used in a cream form to treat skin the part of the hair visible conditions. hair shaft: above the skin. cu•ti•cle: the strip of hardened skin a chemical present in cells at the base and side of fingernails and his•ta•mine: throughout the body and released during toenails. an allergic reaction. cyst: a sac that contains a gas, liquid, : an allergic reaction in which the or semi-solid substance. hives skin becomes covered with small or large der•ma•ti•tis: inflammation of the skin. clusters of itchy, red bumps. It can occur as a result of an infection, eating a certain der•ma•tol•o•gist: a skin doctor. food, or taking a certain medication. der•ma•tol•o•gy: the study of the skin. hy•a•lu•ron•ic ac•id: substance der•mis: the middle layer of skin. naturally found in the body that helps to lubricate the joints. di•a•be•tes: a set of illnesses character- ized by improper amounts of glucose im•mune sys•tem: the coordinated (sugar) in the blood. responses of the body that serve to protect it against outside invaders such dia•per rash: a skin irritation of a as viruses and bacteria. baby’s bottom and/or genitals caused by prolonged exposure to waste. im•pe•ti•go: a contagious bacterial skin infection. ec•crine glands: glands that produce sweat when we’re hot, stressed, or experi- in•fec•tion: invasion of body tissue by encing heavy emotions. a virus or harmful bacteria, resulting in disease. e•las•tin: a protein found in the connective tissue of skin. in•teg•u•men•ta•ry sys•tem: the bodily system consisting of the skin and its ep•i•der•mis: the top layer of skin. related parts. ep•i•neph•rine: an injection of the jaun•dice: a yellowish discoloration hormone adrenaline used to treat life- of the skin or eyes that is a symptom of threatening allergic reactions caused by an underlying illness. insect bites, foods, medications, latex, and other agents. ke•loid: red, raised scar tissue. ec•ze•ma: an allergic reaction with ker•a•tin: a tough protein that is found symptoms that affect the skin. This itchy, in the epidermis, nails and hair. reddening, flaking, and peeling of the skin Lan•ger•hans cells: part of the immune often begins in childhood. system found in the epidermis. eu•mel•a•nin: the melanin that pro- la•nu•go: pale, soft, fine hair that covers duces a brown to black color in the skin. a newborn’s body. fol•lic•u•li•tis: inflammation of a hair le•sion: an infected or diseased patch follicle. of skin. fun•gus: a living thing that decomposes liv•er spot: a harmless discoloration of dead plant and animal material. Some skin caused by sun-damage often occur- skin conditions are caused by fungi. ring in old age. gland: a cell that produces a secretion for lu•nu•la: the half-circle at the base of use elsewhere in the body. 66 each nail. Glossary lu•pus: a set of diseases that affect the scab: crust over a wound. skin and joints. scar: mark left on the skin after a lymph: a clear bodily fluid containing wound has healed. white blood cells that removes bacteria : an internal disease from the tissues, transports fat from the scle•ro•der•ma whose symptoms include hardening of small intestine, and supplies mature the skin. lymphocytes to the blood. se•ba•ceous: secreting an oily ma•trix: the root of the nail. substance. me•dul•la: inner core of certain body oily substance that is secreted structures, including hair. se•bum: by the sebaceous glands. mel•a•nin: dark pigment found in skin : the organ that covers the outside and hair. skin of the body. mel•an•o•cytes: cells that produce the : part of the epidermis. melanin, the pigment that colors our squa•mous cell skin, hair, and eyes. stra•tum cor•ne•um: the outer layer of the epidermis, consisting of dead skin mel•a•no•ma: a fast-growing, danger- cells. ous, malignant skin cancer. stretch mark: a shiny line on the skin mil•i•a: enlarged oil glands. caused by the prolonged stretching of mole: congenital growth on the skin. the skin and the weakening of elastic tissues. ne•o•na•tal ac•ne: acne that affects newborns. sub•cu•ta•ne•ous tis•sue: the fatty bottom layer of skin. nerves: the network of cells that trans- mit signals from all parts of the body to sun•burn: skin inflammation caused and from the brain. by sun exposure. non-com•e•do•gen•ic: not tending to sun•screen: a cream or lotion used to clog pores. protect the skin from the damaging ultraviolet rays of the sun. or•gan: a group of tissues that perform a specific function. symp•tom: a sign of a problem, such as a disease. phe•o•mel•a•nin: the melanin that produces a red to yellow color in the vi•rus: a tiny organism that carries skin. disease. It spreads throughout the body by using the body’s cells to make copies pig•ment: skin coloring. of the virus. pim•ple: a hair follicle clogged with vit•i•li•go: skin disorder that causes sebum and skin cell debris. the skin to lose pigment. pore: small opening in the skin. white•head: type of acne where the pso•ri•a•sis: a skin condition where hair follicle is totally blocked. the skin cells reproduce too quickly. wrin•kle: line or crease in the skin, pu•ber•ty: the stage of adolescence usually caused by age or over exposure where a person can sexually reproduce. to the sun’s radiation. rash: skin outbreak. ro•sa•ce•a: skin disease that makes the face look red. 67

Acknowledgements

Dermatology Content Author Reviewers/Advisors Kirstin Fearnley, AAAS Hassan Galadari, MD, MBBS Resident Department of Dermatology, Boston Medical Project Staff and Consultants Center, Tufts-New England Medical Center Bob Hirshon, Senior Project Director Sidney Hornby, MS Suzanne Thurston, Project Manager Group Leader – Scientific Affairs Ann Marie Williams, Art Director Neutrogena Corp. Maria Sosa, Editor-in-Chief Pamela Strumpf Norden, MD, MBA Renee Stockdale-Homick, Program Assistant Professor and Director of Medical Associate Student Education Kirstin Fearnley, Program Associate Department of Dermatology, Tufts Sarah Ingraffea, Senor Project Coordinator University School of Medicine, Krauss Dermatology Heather Malcomson, Review Coordinator Amani Rushing, Project Associate Maggie Johnson Sliker, Photo Researcher

This publication was funded by Neutrogena and is part of the Skin Deep Project. Neutrogena’s support and interest in providing quality science education resources to teachers, students and the community is greatly appreciated.

69 Skin: The Science Inside

Photo Credits: Cover: Eyewire Images 1: Photos.com 2: Photos.com 3: AAAS 4: National Cancer Institute/NIH 5: Anatomical Travelogue/Science Photo Library 6: Bsip, Jacopin/Science Photo Library 8: Photos.com 9: Photos.com 11: Robert W. Ginn/Photoedit 13: Photo courtesy of the Indian Health Service/U.S. Dept. of Health and Human Services 14: A.D.A.M. 16: (left) Michael Newman/PhotoEdit; (right): Bsip Estiot/Science Photo Library 18: Photos.com 19: Photos.com 21: (left, top) Nicole Owens, MD; (left, center): Shahbaz A. Janjua, MD; (left, bottom) Kosman Sadek Dikry, MD; (right, top): Eric Ehrsam, MD; (right, center) Bernard Cohen, MD; (right, bottom): Bermard Cohen,MD. All courtesy of Dermatlas; www.dermatlas.org 23: Photos.com 24: Reprinted with permission from the American Academy of Dermatology. All rights reserved. 25: Bsip, Gilles/Science Photo Library 26: Ian Boddy/Science Photo Library 27: Reprinted with permission from the American Academy of Dermatology. All rights reserved. 29: Sophie Jacopin/PhotoResearchers, Inc. 30: (left) Reprinted with permission from the American Academy of Dermatology. All rights reserved.; (right) AJPhoto/Photo Researchers, Inc. 31: Laurent/Louise Eve/Photo Researchers, Inc. 32: Ian Hooton/Science Photo Library 34: National Cancer Institute/NIH 35: National Cancer Institute/NIH 37: Skin Cancer Foundation/NIH 39: Philippe Psaila/Science Photo Library 40: Photos.com 41: Photo courtesy of National Psoriasis Foundation 42: Photos.com 45: Photos.com 46: Photos.com 70 1200 New York Avenue, NW Washington, DC 20005 USA 202-326-6670 • www.aaas.org